Rectifier network assembly

ABSTRACT

In a rectifier assembly comprising diodes that have wire terminals projecting axially in opposite directions from a cylindrical body, permanent connections between diode terminals comprise crimp connectors integral with terminal members such as plug jacks. The terminal members are seated in bores in a plug body which is partway received in an open topped metal casing. The casing is filled with epoxy that embeds the diodes, their connections with the terminal members and part of the plug body.

I United States Patent [151 3,678,366 Tharman 5] July 18, 1972 54]RECTIFIER NETWORK ASSEMBLY 3,184,648 5/1965 Brown et al. ..174/s2 PE x3,249,827 5/1966 Benda et a1 ..l74/52 PE X [72] lnventor: Paul A.Thurman, Milwaukee, Wis.

73 As n 2 B i & a C Primary Examiner-William M. Shoop,Jr. 1 Sig ee g iwis a on orporafion wau Attorney-Ira Milton Jones [22] Filed: July 30,1971 [57] ABSTRACT [21] Appl. No.: 167,691 In a rectifier assemblycomprising diodes that have wire terminals projecting axially inopposite directions from a cylindrical body, permanent connectionsbetween diode terminals [52] [1-8. R, PE, ri crimp onnectors integralterminal members 151 such as plug jacks. The terminal members are seatedin bores [51] Int. Cl. ..l-l02m 7/00 in a lug body which is partwayreceived in an open topped [58] Field of Search ..l74/52 PE; 307/150,151; metal casing. The casing is filled with epoxy that embeds the321/2, 8 diodes, their connections with the terminal members and part ofthe plug body. [56] References Cited UNITED STATES PATENTS 5 Claims, 6Drawing Figures 3,131,331 4/1964 Ray ..317/123 Z0] Z0} iO\ (0/ [2O zf-Z2 L P Z2 7 (o Z3 Z3 3 I5 Bi 1 54 9 I Q l I 35 31 IR w i Z4 f I4 J )k N\25 PATENTEDJuLwmn 3,678,366

sum 1 BF 3 INVE'NTOR Paul A- Tfisrman E Y W AT'roR Y mmmmm 3,678,366

SHEET 3 OF 3 ZAC INVENTOR PauZA TZ-zarman (AC BY ATTQRN Y RECTIFIERNETWORK ASSEMBLY This invention relates to means for connecting andmounting small diodes comprising a full-wave rectifier network and formaking detachable electrical connections to that network; and theinvention has more particular reference to a very simple, compact andinexpensive assembly comprising diodes, means connecting the diodes in afull-wave rectifier network, and means for making plug-in connectionsbetween the rectifier network, a source of alternating current and ad.c. load circuit.

Full-wave rectifier networks are finding increasing application inaccessories for small single-cylinder gasoline engines of the type usedfor powering lawn mowers, garden tractors, snow blowers and similarmachines. In many cases such engines are manufactured with a more orless integral alternator that comprises permanent magnets carried by theengine flywheel and a stator mounted on the engine body adjacent to theflywheel. The alternator serves as a source of current for batterycharging or for other purposes that require its a.c. output to beconverted to d.c. The rectifier for effecting such conversion comprisessmall solid state diodes which are connected with one another in abridge arrangement, and which must also be connectable with the a.c.input source and the d.c. load circuit.

In general, structure comprising the rectifier network and itsconnections must provide a protecting enclosure for the diodes and theconnections between them and a heat sink for the diodes, must providefor readily detachably connecting the rectifier network with itsassociated input and output circuits to facilitate assembly andservicing of the engine, and should so support all of its componentsthat the connections between them are immune to the efiects ofvibration. These are basic mechanical requirements for the structure,but competitive conditions in the small engine and electrical equipmentindustries have added another requirement which is at least as demandingas those dictated by function, namely the requirement for utmostminimization of cost without the slightest compromise with quality.

A prior structure that served the same purpose as the one of thisinvention comprised a small block-like capsule in which the diodes ofthe rectifier network were embedded and from one side of which threewires led to a plug connector. A metal bushing through the center of thecapsule provided for mounting it by means of a single screw or rivet andalso served as a ground connection and as a heat sink for the diodes.The plug connector was provided with integral clips by which it wassecured to a bracket that was supported by two screws or rivets. Thatprior structure embodied a high degree of engineering skill, wasfunctionally satisfactory in all respects, and was not unduly expensiveconsidering its nature and purpose.

Nevertheless, it is the general object of this invention to pro vide anassembly which performs all of the functions and possesses all of theadvantages of that prior structure but which can be manufactured atroughly half its cost, can be assembled to an engine with a lessernumber of operations to afford a further cost saving, and is alsosuperior to the prior structure in sturdiness and dependability so thatthe consumer derives a material benefit from the present invention evenwhen the cost savings that it achieves cannot be passed on to himbecause of economic conditions.

It is also an object of this invention to provide an assembly comprisingdiodes permanently connected in a rectifier network and means for makingreadily disconnectable connections to them, which structure is extremelycompact and inexpensive, nicely fulfills all of the mechanicalrequirements set forth above, and has the further important advantage ofhaving no unsupported conductors leading from one component of theassembly to another, thus eliminating both the cost of such conductorsand the potential troubles that can be caused by their breaking.

Another and more specific object of the invention is to providemechanical structure comprising small diodes connected in a rectifiernetwork, wherein the terminals of the diodes have secure solderlessconnections with one another that also comprise quick disconnectterminals for connecting the rectifier network with input and outputcircuits.

It is also a specific object of this invention to provide a mounting andenclosure for small diodes comprising a rectifier network, whereby thediodes and the connections between them, as well as their connections toplug-in terminals, are all encapsulated, to render the assemblysubstantially immune to moisture and vibration, and wherein the diodesare provided with an efiective heat sink.

With these observations and objectives in mind, the manner in which theinvention achieves its purpose will be appreciated from the followingdescription and the accompanying drawings, which exemplify theinvention, it being understood that changes may be made in the specificapparatus disclosed herein without departing from the essentials of theinvention set forth in the appended claims.

The accompanying drawings illustrate one complete example of anembodiment of the invention constructed according to the best mode sofar devised for the practical application of the principles thereof, andin which:

FIG. 1 is a view in elevation of a blower housing for a single cylindergasoline engine, upon which there is mounted a rectifier networkassembly embodying the principles of this invention;

FIG. 2 is a perspective view of the rectifier network assembly of thisinvention, shown in disassembled relationship to a plug which cooperateswith it to provide for connecting the rectifier network with input andoutput circuits;

FIG. 3 is a view in vertical section of the rectifier network assembly,but without potting material;

FIG. 4 is a top plan view of the assembly shown in FIG. 3;

FIG. 5 is a group perspective view of the plug body and casing of theassembly of this invention; and

FIG. 6 is a schematic diagram of the circuit provided by the assembly ofthis invention.

Referring now more particularly to the accompanying drawings, thenumeral 5 designates generally a blower housing or shroud for a singlecylinder gasoline engine of the type used for powering lawn mowers,small tractors and the like. The shroud 5 embraces the engine body toguide cooling air across the cylinder and crankcase portions of theengine from a flywheel blower (not shown). The rectifier networkassembly 6 of this invention is mounted on a bracket 7 on the shroud, atone side of a portion of the shroud that is adjacent to the flywheel,and it can in fact utilize the same mounting holes that served forsecurement of the plug connector alone of the above described priorassembly.

In general, the rectifier network assembly 6 comprises four diodes 8, aplug body 9 of insulating material which houses three plug-in terminalelements 10 that are connected with certain of the diodes, a metalcasing 11, and a body 12 of hardened potting or encapsulating materialsuch as epoxy that secures the plug body 9 in the casing and embeds thediodes.

Each of the diodes 8 is of the solid state type and comprises, as isconventional in low power applications, a small cylindrical body 14 anda pair of wires 15 that extend substantially axially from opposite endsof the body and comprise the terminals of the diode. For the diodes tocooperate in a full-wave rectifier network, each must have its terminalsconnected with a terminal of each of two other diodes, in thearrangement illustrated in FIG. 6; and each connected pair of terminalsmust also be connectable with a terminal of a circuit associated withthe rectifier network.

The means connecting each pair of diode terminals comprises a solderlesscrimp connector 17 that is integral with an element that serves forconnection of the rectifier network with its associated circuits. Inthis case, three of the crimp connectors are on the plug-in temrinalelements 10, and the fourth is on a terminal lug 19 that provides forgrounding one of the d.c. output terminals of the rectifier network(preferably the negative one) to the blower shroud and, through it, tothe engine body. If the rectifier network is not to be grounded, allfour of the crimp connectors would obviously be on plug-in terminalelements 10.

As shown, the temiinal elements are female ones, in the nature of smalltubular plug jacks of a commercially available type, adapted tocooperate with snugly fitting pin-like male plug members. The terminalelements are seated in the plug body 9, which can be molded of a plasticinsulating material such as nylon. The plug body is relatively long andnarrow and has four parallel bores 20 extending heightwise through itfrom one of its narrow faces to the other, arranged in a row along itslength. Each of the bores accommodates one of the plug-in terminalelements 10. In the illustrated embodiment, one of the bores is notoccupied by a terminal element in view of the provision for groundingthe dc. side of the rectifier network, but that bore is available foranother terminal element if ungrounded circuits are desired.

Each of the plug-in terminal elements has radially projecting integraltangs 22 and 23 that are spaced from both ends of its tubular bodyportion. They pem1it the temiinal element to be inserted axially intothe plug body 9 from the bottom thereof, but once the element has beenpushed all the way into the plug body, the tangs engage circumferentialshoulders in the plug body, defined by different diameter portions ofthe bore, to confine the terminal element against axial displacement.Each of the bores 20 has a substantially enlarged diameter lower endportion to accommodate the crimp connector 17 at the rear of theterminal element.

Before they are secured to the crimp connectors, all of the terminalwires of the diodes are cut to the same length, and with the wirestrimmed and connected and the terminal elements installed in the plugbody, the diodes can be readily arranged as shown in FIGS. 3 and 4, withthe two diodes that are connected to the terminal lug 19 disposedalongside one wide face of the plug body, as at 24, and the other twodirectly beneath its narrow bottom face, as at 25. The terminal lug 19projects toward one narrow side of the plug body, and the two diodesthat have terminals connected to it have their other terminals connectedwith terminal elements 10 in the two bores 20 that are nearest said sideof the plug body. With the diodes and terminal elements arranged as justdescribed, the unconnected terminals of the several diodes are wellseparated from one another.

The metal casing 11 in which the plug body and diodes are received ispreferably made as a generally cup-shaped die casting, of zinc or thelike. It has relatively wide front and rear end walls 27 and 28,relatively narrow side walls 29, and a bottom wall 30, but it is open atits top. Along the junction of each of its side walls with its rear wallit has a heightwise extending boss or ear 31 that is bored to receive amounting fastener such as a screw 33 or a rivet. Each of these mountingbosses has a relatively wide, flat top surface, so that the terminal lug19 can be clamped flatwise against it by the fastener that extendstherethrough to make a good grounding connection. A small tit 34projects up from the top of the casing in a position to be engaged bythe shank of the terminal lug and hold the same against rotation withthe screw 33 as the screw is tightened.

, Projecting laterally outwardly from each narrow side surface of theplug body 9, near the bottom thereof, is a lug 35 that is received in aninwardly opening groove 36 in the casing to properly locate the plugbody relative to the casing during its assembly thereinto. The grooves36, which extend heightwise along the side walls 29 of the casing, atthe inner surfaces thereof, are closer to the front wall 27 of thecasing than to its rear wall, They of course open to the top of thecasing, but they terminate a distance from its bottom to defineshoulders 37 that cooperate with the lugs 35 on the plug body to holdthe latter spaced a distance above the bottom wall of the casing. Thespace between the bottom of the plug body and the bottom wall of thecasing accommodates the two diodes that underlie the plug body at 25.The space between the plug body and the rear wall 28 of the casingaccommodates the other two diodes, at 24, that are disposed alongsidethe plug body.

The plug body can be provided with a rib 39 that engages a comer of asmall pad 40 on the inner surface of the front wall 27 of the casing, tocause the plug body to engage one side wall 29 of the casing with aneasy press fit by which the plug body is retained against accidentaldisplacement until the potting material 12 has cured. I I

The two diodes that are alongside the plug body at 25 are disposed belowthe top of the casing, hence when the casing is filled to its top withhardenable liquid potting or encapsulating material, such as epoxy, allof the diodes are embedded in such material and are thus protected byit. The epoxy also serves to transmit heat from the diodes to the metalcasing so that the latter can serve as a heat sink.

The potting material, which ordinarily does not bond well to nylon andsimilar plastics, covers the outer faces of the lugs 35 on the plug bodyand thus anchors the plug body into the casing. Note that the pottingmaterial also fills those portions of the bores 20 in the plug body thatcontain the crimp connectors on the terminal elements 17, so that allpermanent connections in the assembly are embedded and thus rigidlysupported, and all unconnected diode terminals are insulated from oneanother by the potting material.

The plug body 9 projects a distance above the top of the casing forcooperation with a plug member 42 that fits over the plug body and hasconventional pin-like male terminal members therein, connected withconductors 43 that lead to and from the input and output circuits.

From the foregoing description taken with the accompanying drawings itwill be apparent that this invention provides a very compact,inexpensive and rugged assembly comprising diodes permanently connectedin a rectifier network and means for readily detachably connecting therectifier network with its associated input and output circuits, whichassembly afi'ords protection to the diodes against moisture andmechanical impacts and vibration, provides a heat sink for them, andmaintains good, rigid connections between their terminals and terminalelements that provide for connections to the rectifier network.

Those skilled in the art will appreciate that the invention can beembodied in forms other than as herein disclosed for purposes ofillustration.

The invention is defined by the following claims:

I claim:

1. Means permanently connecting four diodes with one another in a fullwave rectifier network and providing for readily disconnectableconnection of the rectifier network with a source of alternating currentand with a direct current load circuit, each of the diodes being of thetype comprising a body from which wires that comprise terminals extendin opposite directions, said means comprising:

A. crimped connector means, each comprising a part of a plug-in terminalelement, connecting terminals of the diodes;

B. a connector plug body of insulating material having borestherethrough which open to opposite faces thereof and in which saidplug-in terminal elements are seated with all of said plug-in terminalelements accessible at one of said faces, the diodes being outwardlyadjacent to the other of said faces;

C. a metal casing in which the plug body and the diodes are received,the plug body having at least its said one face exposed at the exteriorof said casing; and

D. a mass of hardened plastic insulating material in the easing securingthe plug body therein and insulatingly embedding the diodes and theconnector means.

2. The structure of claim 1 wherein said casing has a pair of holestherethrough in which securement means are receivable for fastening thecasing in electrically grounded relationship to structure that carriesthe casing, further characterized by:

one of said crimped connector means comprising a terminal lug whichoverlies a face of the casing to which one of said holes opens, to besecured to the casing by one of said securement means and to thus groundthe rectifier network.

3. In combination with four diodes, each of the type comprising a bodyand a pair of wires that extend in opposite directions from the body andserve as terminals for the diode, means permanently connecting thediodes in a full-wave rectifier network and providing for its connectionwith a source of alternating current and with a direct current loadcircuit:

A. a plurality of plug-in terminal elements each of the type having anintegral crimp connector, the crimp connector of each terminal elementbeing connected to one of the wires of each of a pair of diodes toconnect them;

B. a connector plug body of insulating material having a plurality ofbores therethrough that open to top and bottom faces of said body, saidterminal elements being seated in said bores and being accessible tomating terminal members at the top face of the body, the diodes beingoutwardly adjacent to the lower portion of said body;

C. a generally cup-like metal casing, the bodies of the diodes beingwholly received within said casing and at least the bottom portion ofthe plug body being received therein; and

D. a mass of hardened plastic insulating material in the casing bondingthe plug body thereto and embedding the diodes and their connectionswith the temiinal elements. 4. The combination of claim 3, in which saidmetal casing has opposite side walls and opposite end walls, furthercharacterized by:

E. the casing having opposite inwardly opening grooves in its side wallsthat open to its top;

F. the plug body having lugs which are received in said grooves andwhich are overlain by portions of said mass to hold the plug bodyagainst displacement out of the casing, said lugs cooperating with thegrooves in the casing and with said mass to hold the plug body spacedfrom one of the end walls of the casing and thus define a compartment inthe casing in which diode bodies are received.

5. The combination of claim 4, in which the metal casing has a bottomwall, further characterized by:

G. said grooves terminating a distance above said bottom wall to defineupwardly facing shoulders upon which said lugs rest and which cooperatewith the lugs to maintain the plug body spaced above the bottom wall,diodes being disposed in the space between the plug body and the bottomwall.

1. Means permanently connecting four diodes with one another in a fullwave rectifier network and providing for readily disconnectableconnection of the rectifier network with a source of alternating currentand with a direct current load circuit, each of the diodes being of thetype comprising a body from which wires that comprise terminals extendin opposite directions, said means comprising: A. crimped connectormeans, each comprising a part of a plug-in terminal element, connectingterminals of the diodes; B. a connector plug body of insulating materialhaving bores therethrough which open to opposite faces thereof and inwhich said plug-in terminal elements are seated with all of said plug-interminal elements accessible at one of said faces, the diodes beingoutwardly adjacent to the other of said faces; C. a metal casing inwhich the plug body and the diodes are received, the plug body having atleast its said one face exposed at the exterior of said casing; and D. amass of hardened plastic insulating material in the casing securing theplug body therein and insulatingly embedding the diodes and theconnector means.
 2. The structure of claim 1 wherein said casing has apair of holes therethrough in which securement means are receivable forfastening the casing in electrically grounded relationship to structurethat carries the casing, further characterized by: one of said crimpedconnector means comprising a terminal lug which overlies a face of thecasing to which one of said holes opens, to be secured to the casing byone of said securement means and to thus ground the rectifier network.3. In combination with four diodes, each of the type comprising a bodyand a pair of wires that extend in opposite directions from the body andserve as terminals for the diode, means permanently connecting thediodes in a full-wave rectifier network and providing for its connectionwith a source of alternating current and with a direct current loadcircuit: A. a plurality of plug-in terminal elements each of the typehaving an integral crimp connector, the crimp connector of each terminalelement being connected to one of the wires of each of a pair of diodesto connect them; B. a connector plug body of insulating material havinga plurality of bores therethrough that open to top and bottom faces ofsaid body, said terminal elements being seated in said bores and beingaccessible to mating terminal members at the top face of the body, thediodes being outwardly adjacent to the lower portion of said body; C. agenerally cup-like metal casing, the bodies of the diodes being whollyreceived within said casing and at least the bottom portion of the plugbody being received therein; and D. a mass of hardened plasticinsulating material in the casing bonding the plug body thereto andembedding the diodes and their connections with the terminal elements.4. The combination of claim 3, in which said metal casing has oppositeside walls and opposite end walls, further characterized by: E. thecasing having opposite inwardly opening grooves in its side walls thatopen to its top; F. the plug body having lugs which are received in saidgrooves and which are overlain by portions of said mass to hold the plugbody against displacement out of the casing, said lugs cooperating withthe grooves in the casing and with said mass to hold the plug bodyspaced from one of the end walls of the casing and thus define acompartment in the casing in which diode bodies are received.
 5. Thecombination of claim 4, in which the metal casing has a bottom wall,further characterized by: G. said grooves terminating a distance abovesaid bottom wall to define upwardly facing shoulders upon which saidlugs rest and which cooperate with the lugs to maintain the plug bodyspaced above the bottom wall, diodes being disposed in the space betweenthe plug body aNd the bottom wall.